Search for the flavor-changing neutral-current decay t→Zq in pp̄ collisions at s=1.96TeV
Physical Review Letters 101:19 (2008)
Abstract:
We report a search for the flavor-changing neutral-current decay of the top quark t→Zq (q=u, c) in pp̄ collisions at s=1.96TeV using a data sample corresponding to an integrated luminosity of 1.9fb-1 collected by the CDF II detector. This decay is strongly suppressed in the standard model and an observation of a signal at the Fermilab Tevatron would be an indication of physics beyond the standard model. Using Z+4 jet final state candidate events, with and without an identified bottom quark jet, we obtain an upper limit of B(t→Zq)<3.7% at 95% C.L. © 2008 The American Physical Society.Top Quark Mass Measurement in the tt-bar All Hadronic Channel using a Matrix Element Technique in ppbar Collisions at sqrt s = 1.96 TeV
ArXiv 0811.1062 (2008)
Measurement of W-Boson Helicity Fractions in Top-Quark Decays Using costheta*
ArXiv 0811.0344 (2008)
Observation of Υ(2S)→ηΥ(1S) and search for related transitions
Physical Review Letters 101:19 (2008)
Abstract:
We report the first observation of Υ(2S)→ηΥ(1S), with a branching fraction B=(2.1-0.6+0.7(stat)±0.3(syst))×10-4 and a statistical significance 5.3σ. Data were acquired with the CLEO III detector at the CESR e+e- symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10-4 are B(Υ(2S)→π0Υ(1S))<1.8, B(Υ(3S)→ηΥ(1S))<1.8, B(Υ(3S)→π0Υ(1S)) <0.7, and B(Υ(3S)→π0Υ(2S))<5.1. © 2008 The American Physical Society.A search for high-mass resonances decaying to dimuons at CDF
ArXiv 0811.0053 (2008)